Effect of altitudinal variation on the soil characteristics in sal (Shorea robusta gaertn.) forests of eastern Nepal

Abstract

Physico-chemical properties of forest soil depends on a variety of natural factors, the most important are variation in altitude, vegetation cover and microbial activities. The present study was conducted to understand the effect of variation in altitude in the soil characteristics in Tarai Sal forest (TSF) and Hill Sal forest (HSF), of eastern Nepal. Soil samples were collected from thirty plots randomly in each forest from 0-15cm and 15-30cm depths in May 2012. Both forests had sandy loam type of soil texture. However, the percentage composition of soil particles varies within the forest sites. Soil moisture was higher in TSF. It was maximum in the rainy season in both forests. Water holding capacity was slightly higher in TSF. Bulk density was higher in TSF and it increased with soil depth in both forests. The pH value was slightly higher in HSF than TSF however, the value increased in lower soil depth in both forest stands. In the upper soil layer (0-15cm) soil organic carbon (SOC) was higher in HSF (2.09%) than TSF (1.6%). Similarly, total nitrogen (TN) was also higher in HSF (0.173%) than in TSF (0.129%) while total phosphorus (TP) was more or less same in both forest stands. The potassium (K) a soil extractable nutrient also showed higher value in HSF (312.13 µg g . The values of SOC, TN, TP and K decreased in lower depth (15-30cm) in both forest stands. In conclusion, variation in altitude causes difference in the microclimatic condition which resulted into the alternation in soil characteristics. AbstractPhysico-chemical properties of forest soil depends on a variety of natural factors, the most important are variation in altitude, vegetation cover and microbial activities. The present study was conducted to understand the effect of variation in altitude in

Flowering Plant Diversity of Differentially Disturbed Region of Terai Sal (Shorea robusta) Forest in Eastern Nepal

“…Habitat Characteristics and Human disturbances Charali Sal (Shorea robusta) forest is one of the characteristic forests in the Terai and lower foothills of Nepal, which have been exploited since history as the timber source (Gautam & Devoe, 2006;Rahman et al, 2009;Rautiainen & Suoheimo, 1997). These forests have been affected from various anthropogenic activities such as, selective felling, invasion of alien species, uncontrolled grazing, annual forest fires, and over-exploitation of resources (Bhattarai, 2017;Rahman et al, 2009;Rautiainen & Suoheimo, 1997). Mimosa diplotricha cover (%) 1.33 ± 1.00 a 0.00 a 0.67 ± 0.51…”

“…A higher number of flowering plant species were recorded in disturbed sites (90 total species; 89, identified species) compared to undisturbed sites (86 total; 80 identified) (Table 2). A floristic survey carried out by Bhattarai (2017) in similar Sal forest located in Jalthal, Jhapa documented 150 flowering plant species belonging to 128 genera under 75 families. In the similar kind of study in a Sal forest in Gorakhpur, India, Pandey and Shukla (2003) recorded a total of 208 plant species representing 165 genera and 72 familes.…”

“…There have been numerous studies which explore vegetation, wildlife and other associated aspects of biodiversity in other parts of Nepal, however, only few tends to focus in eastern Nepal, particularly in Tropical belt. In recent years some researches have been focused in the tropical Sal forest of Jhapa district (Bhattarai, 2008(Bhattarai, , 2017Bhattarai & Mandal, 2018;Sharma et al, 2021aSharma et al, , 2021b and few new plant species have also been added to the flora of Nepal (Bhandari et al, 2021;Neupane et al, 2024;Sharma et al, 2021a). Despite of recent commendable approach to study the Tropical flora in eastern Nepal, the Charali Sal forest (also known as Charali Nichajhoda forest) was left unexplored.…”

A report of Siwalik forest around Letang Raja-Rani wetland, Morang, eastern Nepal

“…The occurrence of dead stump marked the cutting of trees. ( Bhattarai and Mandal, 2016) Regulating human encroachment to ensure natural regeneration of species to maintain the viability of Letang Raja-Rani wetland site and integrity of the local ecosystem is strongly recommended.…”

Threats to the Critically Endangered yellow-headed tortoise Indotestudo elongata in Jalthal Forest, eastern lowland Nepal

“…It spans 62.6 km 2 and comprises floristic elements from the Indo-Malayan Floristic Region, consisting of dominant sal Shorea robusta forest and mixed deciduous forest (Thapa et al, 2003). The climate is mostly tropical monsoon with a dry and warm summer (March–mid May), a humid and warm period (mid May–October) and a dry and cold winter (November–February; Bhattarai, 2017). Mean annual minimum and maximum temperatures are 10 and 33 °C, respectively.…”